/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #10b981;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.nav {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-research {
    margin-bottom: 2.5rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.research-text {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    opacity: 0.9;
    font-weight: 500;
}

.research-links {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.95rem;
}

.research-label {
    opacity: 0.9;
    font-weight: 500;
    margin-right: 0.25rem;
}

.research-link {
    color: white;
    text-decoration: underline;
    text-decoration-color: rgba(255, 255, 255, 0.5);
    text-underline-offset: 3px;
    transition: all 0.3s;
    opacity: 0.95;
}

.research-link:hover {
    opacity: 1;
    text-decoration-color: white;
    text-decoration-thickness: 2px;
}

.research-separator {
    opacity: 0.6;
    margin: 0 0.25rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: var(--bg-white);
    color: var(--primary-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

.hero-note {
    margin-top: 1rem;
    opacity: 0.9;
    font-size: 0.9rem;
}

/* Problem Section */
.problem {
    padding: 4rem 0;
    background: var(--bg-light);
}

.problem h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.problem-item {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.75rem;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.problem-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.problem-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.problem-item p {
    color: var(--text-light);
}

/* Science Section */
.science {
    padding: 4rem 0;
    background: var(--bg-white);
}

.science h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.science-lead {
    font-size: 1.25rem;
    text-align: center;
    color: var(--text-dark);
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.science-studies {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.study {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: 0.75rem;
    border-left: 4px solid var(--primary-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.study:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.study h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 700;
}

.study p {
    color: var(--text-dark);
    line-height: 1.7;
    margin-bottom: 1.25rem;
    font-size: 1.05rem;
}

.study em {
    font-style: italic;
    color: var(--text-dark);
}

.study-link {
    display: inline-block;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s;
}

.study-link:hover {
    color: var(--primary-dark);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* How It Works Section */
.how-it-works {
    padding: 4rem 0;
    background: var(--bg-light);
}

.how-it-works h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.steps {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.step-number {
    background: var(--primary-color);
    color: white;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.step-content p {
    color: var(--text-light);
}

/* Features Section */
.features {
    padding: 4rem 0;
    background: var(--bg-white);
}

.features h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature {
    text-align: center;
    padding: 2rem;
    background: var(--bg-light);
    border-radius: 0.75rem;
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.feature p {
    color: var(--text-light);
}

/* Benefits Section */
.benefits {
    padding: 4rem 0;
    background: var(--bg-light);
}

.benefits h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.benefits-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.benefit-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.checkmark {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.benefit-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.benefit-item p {
    color: var(--text-light);
}

/* FAQ Section */
.faq {
    padding: 4rem 0;
    background: var(--bg-white);
}

.faq h2 {
    text-align: center;
    font-size: 2.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.faq-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 3rem;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    overflow: hidden;
    background: var(--bg-white);
    transition: box-shadow 0.3s;
}

.faq-item:hover {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
    transition: background-color 0.3s;
}

.faq-question:hover {
    background-color: var(--bg-light);
}

.faq-question span:first-child {
    flex: 1;
    padding-right: 1rem;
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--primary-color);
    transition: transform 0.3s;
    flex-shrink: 0;
    width: 24px;
    text-align: center;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
    padding: 0 1.5rem;
}

.faq-item.active .faq-answer {
    max-height: 2000px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: var(--text-dark);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.faq-answer p:last-child {
    margin-bottom: 0;
}

.faq-answer ul,
.faq-answer ol {
    margin-bottom: 1rem;
    padding-left: 2rem;
    color: var(--text-dark);
}

.faq-answer li {
    margin-bottom: 0.5rem;
    line-height: 1.7;
}

.faq-answer strong {
    color: var(--text-dark);
    font-weight: 600;
}

.faq-answer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.faq-answer a:hover {
    text-decoration: underline;
}

/* CTA Section */
.cta-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-section > p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.cta-note {
    margin-top: 1rem;
    opacity: 0.9;
    font-size: 0.9rem;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.footer-section h4 {
    margin-bottom: 0.75rem;
    font-size: 1rem;
}

.footer-section a {
    display: block;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    margin-bottom: 0.5rem;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.5rem;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0.5rem;
}

.disclaimer {
    font-size: 0.875rem;
    margin-top: 1rem;
    opacity: 0.6;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .research-text {
        font-size: 0.9rem;
    }

    .research-links {
        font-size: 0.85rem;
        flex-direction: column;
        gap: 0.25rem;
    }

    .research-separator {
        display: none;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .problem h2,
    .science h2,
    .how-it-works h2,
    .features h2,
    .benefits h2,
    .faq h2 {
        font-size: 1.75rem;
    }

    .faq-question {
        font-size: 1rem;
        padding: 1.25rem;
    }

    .faq-answer {
        font-size: 0.95rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 1.25rem 1.25rem;
    }

    .science-lead {
        font-size: 1.1rem;
    }

    .study {
        padding: 1.5rem;
    }

    .study h3 {
        font-size: 1.25rem;
    }

    .study p {
        font-size: 1rem;
    }

    .cta-section h2 {
        font-size: 2rem;
    }

    .step {
        flex-direction: column;
        text-align: center;
    }

    .step-number {
        margin: 0 auto;
    }

    .benefit-item {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 3rem 0;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .problem,
    .science,
    .how-it-works,
    .features,
    .benefits {
        padding: 3rem 0;
    }

    .problem-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}